drivers/edac/edac_pci.c

   1 /*
   2  * EDAC PCI component
   3  *
   4  * Author: Dave Jiang <djiang@mvista.com>
   5  *
   6  * 2007 (c) MontaVista Software, Inc. This file is licensed under
   7  * the terms of the GNU General Public License version 2. This program
   8  * is licensed "as is" without any warranty of any kind, whether express
   9  * or implied.
  10  *
  11  */
  12 #include <linux/module.h>
  13 #include <linux/types.h>
  14 #include <linux/smp.h>
  15 #include <linux/init.h>
  16 #include <linux/sysctl.h>
  17 #include <linux/highmem.h>
  18 #include <linux/timer.h>
  19 #include <linux/slab.h>
  20 #include <linux/spinlock.h>
  21 #include <linux/list.h>
  22 #include <linux/sysdev.h>
  23 #include <linux/ctype.h>
  24 #include <linux/workqueue.h>
  25 #include <asm/uaccess.h>
  26 #include <asm/page.h>
  27
  28 #include "edac_core.h"
  29 #include "edac_module.h"
  30
  31 static DEFINE_MUTEX(edac_pci_ctls_mutex);
  32 static struct list_head edac_pci_list = LIST_HEAD_INIT(edac_pci_list);
  33
  34 static inline void edac_lock_pci_list(void)
  35 {
  36         mutex_lock(&edac_pci_ctls_mutex);
  37 }
  38
  39 static inline void edac_unlock_pci_list(void)
  40 {
  41         mutex_unlock(&edac_pci_ctls_mutex);
  42 }
  43
  44 /*
  45  * The alloc() and free() functions for the 'edac_pci' control info
  46  * structure. The chip driver will allocate one of these for each
  47  * edac_pci it is going to control/register with the EDAC CORE.
  48  */
  49 struct edac_pci_ctl_info *edac_pci_alloc_ctl_info(unsigned int sz_pvt,
  50                                                 const char *edac_pci_name)
  51 {
  52         struct edac_pci_ctl_info *pci;
  53         void *pvt;
  54         unsigned int size;
  55
  56         pci = (struct edac_pci_ctl_info *)0;
  57         pvt = edac_align_ptr(&pci[1], sz_pvt);
  58         size = ((unsigned long)pvt) + sz_pvt;
  59
  60         if ((pci = kzalloc(size, GFP_KERNEL)) == NULL)
  61                 return NULL;
  62
  63         pvt = sz_pvt ? ((char *)pci) + ((unsigned long)pvt) : NULL;
  64
  65         pci->pvt_info = pvt;
  66
  67         pci->op_state = OP_ALLOC;
  68
  69         snprintf(pci->name, strlen(edac_pci_name) + 1, "%s", edac_pci_name);
  70
  71         return pci;
  72 }
  73
  74 EXPORT_SYMBOL_GPL(edac_pci_alloc_ctl_info);
  75
  76 /*
  77  * edac_pci_free_ctl_info()
  78  *      frees the memory allocated by edac_pci_alloc_ctl_info() function
  79  */
  80 void edac_pci_free_ctl_info(struct edac_pci_ctl_info *pci)
  81 {
  82         kfree(pci);
  83 }
  84
  85 EXPORT_SYMBOL_GPL(edac_pci_free_ctl_info);
  86
  87 /*
  88  * find_edac_pci_by_dev()
  89  *      scans the edac_pci list for a specific 'struct device *'
  90  */
  91 static struct edac_pci_ctl_info *find_edac_pci_by_dev(struct device *dev)
  92 {
  93         struct edac_pci_ctl_info *pci;
  94         struct list_head *item;
  95
  96         debugf3("%s()\n", __func__);
  97
  98         list_for_each(item, &edac_pci_list) {
  99                 pci = list_entry(item, struct edac_pci_ctl_info, link);
 100
 101                 if (pci->dev == dev)
 102                         return pci;
 103         }
 104
 105         return NULL;
 106 }
 107
 108 /*
 109  * add_edac_pci_to_global_list
 110  *      Before calling this function, caller must assign a unique value to
 111  *      edac_dev->pci_idx.
 112  *      Return:
 113  *              0 on success
 114  *              1 on failure
 115  */
 116 static int add_edac_pci_to_global_list(struct edac_pci_ctl_info *pci)
 117 {
 118         struct list_head *item, *insert_before;
 119         struct edac_pci_ctl_info *rover;
 120
 121         insert_before = &edac_pci_list;
 122
 123         /* Determine if already on the list */
 124         if (unlikely((rover = find_edac_pci_by_dev(pci->dev)) != NULL))
 125                 goto fail0;
 126
 127         /* Insert in ascending order by 'pci_idx', so find position */
 128         list_for_each(item, &edac_pci_list) {
 129                 rover = list_entry(item, struct edac_pci_ctl_info, link);
 130
 131                 if (rover->pci_idx >= pci->pci_idx) {
 132                         if (unlikely(rover->pci_idx == pci->pci_idx))
 133                                 goto fail1;
 134
 135                         insert_before = item;
 136                         break;
 137                 }
 138         }
 139
 140         list_add_tail_rcu(&pci->link, insert_before);
 141         return 0;
 142
 143 fail0:
 144         edac_printk(KERN_WARNING, EDAC_PCI,
 145                 "%s (%s) %s %s already assigned %d\n",
 146                 rover->dev->bus_id, dev_name(rover),
 147                 rover->mod_name, rover->ctl_name, rover->pci_idx);
 148         return 1;
 149
 150 fail1:
 151         edac_printk(KERN_WARNING, EDAC_PCI,
 152                 "but in low-level driver: attempt to assign\n"
 153                 "\tduplicate pci_idx %d in %s()\n", rover->pci_idx,
 154                 __func__);
 155         return 1;
 156 }
 157
 158 /*
 159  * complete_edac_pci_list_del
 160  */
 161 static void complete_edac_pci_list_del(struct rcu_head *head)
 162 {
 163         struct edac_pci_ctl_info *pci;
 164
 165         pci = container_of(head, struct edac_pci_ctl_info, rcu);
 166         INIT_LIST_HEAD(&pci->link);
 167         complete(&pci->complete);
 168 }
 169
 170 /*
 171  * del_edac_pci_from_global_list
 172  */
 173 static void del_edac_pci_from_global_list(struct edac_pci_ctl_info *pci)
 174 {
 175         list_del_rcu(&pci->link);
 176         init_completion(&pci->complete);
 177         call_rcu(&pci->rcu, complete_edac_pci_list_del);
 178         wait_for_completion(&pci->complete);
 179 }
 180
 181 /*
 182  * edac_pci_find()
 183  *      Search for an edac_pci_ctl_info structure whose index is 'idx'
 184  *
 185  * If found, return a pointer to the structure
 186  * Else return NULL.
 187  *
 188  * Caller must hold pci_ctls_mutex.
 189  */
 190 struct edac_pci_ctl_info *edac_pci_find(int idx)
 191 {
 192         struct list_head *item;
 193         struct edac_pci_ctl_info *pci;
 194
 195         /* Iterage over list, looking for exact match of ID */
 196         list_for_each(item, &edac_pci_list) {
 197                 pci = list_entry(item, struct edac_pci_ctl_info, link);
 198
 199                 if (pci->pci_idx >= idx) {
 200                         if (pci->pci_idx == idx)
 201                                 return pci;
 202
 203                         /* not on list, so terminate early */
 204                         break;
 205                 }
 206         }
 207
 208         return NULL;
 209 }
 210
 211 EXPORT_SYMBOL_GPL(edac_pci_find);
 212
 213 /*
 214  * edac_pci_workq_function()
 215  *      performs the operation scheduled by a workq request
 216  */
 217 static void edac_pci_workq_function(struct work_struct *work_req)
 218 {
 219         struct delayed_work *d_work = (struct delayed_work *)work_req;
 220         struct edac_pci_ctl_info *pci = to_edac_pci_ctl_work(d_work);
 221
 222         edac_lock_pci_list();
 223
 224         if ((pci->op_state == OP_RUNNING_POLL) &&
 225                 (pci->edac_check != NULL) && (edac_pci_get_check_errors()))
 226                 pci->edac_check(pci);
 227
 228         edac_unlock_pci_list();
 229
 230         /* Reschedule */
 231         queue_delayed_work(edac_workqueue, &pci->work,
 232                         msecs_to_jiffies(edac_pci_get_poll_msec()));
 233 }
 234
 235 /*
 236  * edac_pci_workq_setup()
 237  *      initialize a workq item for this edac_pci instance
 238  *      passing in the new delay period in msec
 239  */
 240 static void edac_pci_workq_setup(struct edac_pci_ctl_info *pci,
 241                                  unsigned int msec)
 242 {
 243         debugf0("%s()\n", __func__);
 244
 245         INIT_DELAYED_WORK(&pci->work, edac_pci_workq_function);
 246         queue_delayed_work(edac_workqueue, &pci->work,
 247                         msecs_to_jiffies(edac_pci_get_poll_msec()));
 248 }
 249
 250 /*
 251  * edac_pci_workq_teardown()
 252  *      stop the workq processing on this edac_pci instance
 253  */
 254 static void edac_pci_workq_teardown(struct edac_pci_ctl_info *pci)
 255 {
 256         int status;
 257
 258         status = cancel_delayed_work(&pci->work);
 259         if (status == 0)
 260                 flush_workqueue(edac_workqueue);
 261 }
 262
 263 /*
 264  * edac_pci_reset_delay_period
 265  */
 266 void edac_pci_reset_delay_period(struct edac_pci_ctl_info *pci,
 267                                  unsigned long value)
 268 {
 269         edac_lock_pci_list();
 270
 271         edac_pci_workq_teardown(pci);
 272
 273         edac_pci_workq_setup(pci, value);
 274
 275         edac_unlock_pci_list();
 276 }
 277
 278 EXPORT_SYMBOL_GPL(edac_pci_reset_delay_period);
 279
 280 /*
 281  * edac_pci_add_device: Insert the 'edac_dev' structure into the
 282  * edac_pci global list and create sysfs entries associated with
 283  * edac_pci structure.
 284  * @pci: pointer to the edac_device structure to be added to the list
 285  * @edac_idx: A unique numeric identifier to be assigned to the
 286  * 'edac_pci' structure.
 287  *
 288  * Return:
 289  *      0       Success
 290  *      !0      Failure
 291  */
 292 int edac_pci_add_device(struct edac_pci_ctl_info *pci, int edac_idx)
 293 {
 294         debugf0("%s()\n", __func__);
 295
 296         pci->pci_idx = edac_idx;
 297
 298         edac_lock_pci_list();
 299
 300         if (add_edac_pci_to_global_list(pci))
 301                 goto fail0;
 302
 303         pci->start_time = jiffies;
 304
 305         if (edac_pci_create_sysfs(pci)) {
 306                 edac_pci_printk(pci, KERN_WARNING,
 307                                 "failed to create sysfs pci\n");
 308                 goto fail1;
 309         }
 310
 311         if (pci->edac_check != NULL) {
 312                 pci->op_state = OP_RUNNING_POLL;
 313
 314                 edac_pci_workq_setup(pci, 1000);
 315         } else {
 316                 pci->op_state = OP_RUNNING_INTERRUPT;
 317         }
 318
 319         edac_pci_printk(pci, KERN_INFO,
 320                         "Giving out device to module '%s' controller '%s':"
 321                         " DEV '%s' (%s)\n",
 322                         pci->mod_name,
 323                         pci->ctl_name,
 324                         dev_name(pci), edac_op_state_toString(pci->op_state));
 325
 326         edac_unlock_pci_list();
 327         return 0;
 328
 329 fail1:
 330         del_edac_pci_from_global_list(pci);
 331 fail0:
 332         edac_unlock_pci_list();
 333         return 1;
 334 }
 335
 336 EXPORT_SYMBOL_GPL(edac_pci_add_device);
 337
 338 /*
 339  * edac_pci_del_device()
 340  *      Remove sysfs entries for specified edac_pci structure and
 341  *      then remove edac_pci structure from global list
 342  *
 343  * @dev:
 344  *      Pointer to 'struct device' representing edac_pci structure
 345  *      to remove
 346  *
 347  * Return:
 348  *      Pointer to removed edac_pci structure,
 349  *      or NULL if device not found
 350  */
 351 struct edac_pci_ctl_info *edac_pci_del_device(struct device *dev)
 352 {
 353         struct edac_pci_ctl_info *pci;
 354
 355         debugf0("%s()\n", __func__);
 356
 357         edac_lock_pci_list();
 358
 359         if ((pci = find_edac_pci_by_dev(dev)) == NULL) {
 360                 edac_unlock_pci_list();
 361                 return NULL;
 362         }
 363
 364         pci->op_state = OP_OFFLINE;
 365
 366         edac_pci_workq_teardown(pci);
 367
 368         edac_pci_remove_sysfs(pci);
 369
 370         del_edac_pci_from_global_list(pci);
 371
 372         edac_unlock_pci_list();
 373
 374         edac_printk(KERN_INFO, EDAC_PCI,
 375                 "Removed device %d for %s %s: DEV %s\n",
 376                 pci->pci_idx, pci->mod_name, pci->ctl_name, dev_name(pci));
 377
 378         return pci;
 379 }
 380
 381 EXPORT_SYMBOL_GPL(edac_pci_del_device);
 382
 383 void edac_pci_generic_check(struct edac_pci_ctl_info *pci)
 384 {
 385         edac_pci_do_parity_check();
 386 }
 387
 388 static int edac_pci_idx = 0;
 389 #define EDAC_PCI_GENCTL_NAME    "EDAC PCI controller"
 390
 391 struct edac_pci_gen_data {
 392         int edac_idx;
 393 };
 394
 395 struct edac_pci_ctl_info *edac_pci_create_generic_ctl(struct device *dev,
 396                                                 const char *mod_name)
 397 {
 398         struct edac_pci_ctl_info *pci;
 399         struct edac_pci_gen_data *pdata;
 400
 401         pci = edac_pci_alloc_ctl_info(sizeof(*pdata), EDAC_PCI_GENCTL_NAME);
 402         if (!pci)
 403                 return NULL;
 404
 405         pdata = pci->pvt_info;
 406         pci->dev = dev;
 407         dev_set_drvdata(pci->dev, pci);
 408         pci->dev_name = pci_name(to_pci_dev(dev));
 409
 410         pci->mod_name = mod_name;
 411         pci->ctl_name = EDAC_PCI_GENCTL_NAME;
 412         pci->edac_check = edac_pci_generic_check;
 413
 414         pdata->edac_idx = edac_pci_idx++;
 415
 416         if (edac_pci_add_device(pci, pdata->edac_idx) > 0) {
 417                 debugf3("%s(): failed edac_pci_add_device()\n", __func__);
 418                 edac_pci_free_ctl_info(pci);
 419                 return NULL;
 420         }
 421
 422         return pci;
 423 }
 424
 425 EXPORT_SYMBOL_GPL(edac_pci_create_generic_ctl);
 426
 427 void edac_pci_release_generic_ctl(struct edac_pci_ctl_info *pci)
 428 {
 429         edac_pci_del_device(pci->dev);
 430         edac_pci_free_ctl_info(pci);
 431 }
 432
 433 EXPORT_SYMBOL_GPL(edac_pci_release_generic_ctl);